Although transfusion rate was significantly higher in anemia with ID group than anemia without ID group (33.9%, 20.8%, p = 0.035), preoperative Hb level was also significantly lower in anemia with ID group than anemia without ID group (11.0, 11.4, p = 0.000) (Fig. 4). The gene discussed is GSTM1; the disease is anemia (phenotype).